I called this number back after listening to the vm about a case file.  It's a scam. The man answered the phone and with a very thick India accent stated he was the IRS
I LAUGHED AND TOLD HIM HE Was  a Scam artist  To that he replied he was gonna [***] me so bad Rrally.

This is a call I've gotten twice, claiming that I am being sued by the IRS

Me too. Called twice today saying I'm being sued and to call them. I won't.  Don't know if it's trying to piggyback off my phone number if I call them. Figured it's a scam. If they keep it up, I'll report them.

It's a scam

Scam robo call claiming to be the IRS but not. The IRS will never contact you by telephone... only by mail. These are felons trying to rob you. Do not call them back.